Trends in fast foods and green e-marketing are increasing around the world including Pakistan. Drawing on unique survey data of the year 2023 for urban Pakistan, this study aimed to identify the principal determinants of consumer satisfaction toward green e-marketing of international fast food chains using service quality (SERVQUAL) dimensions and the conventional economics of happiness approach. The overall sample size of 400 respondents was determined by the Yamane method. Applying ordered probit regression analyses, we found that the tangibility dimension in terms of eco-labeling of fast food packaging and the empathy dimension in terms of employees’ understanding of customer needs and preferences according to their age or gender were the most significant and important determinants for consumer satisfaction. Interestingly, monthly expenditures on green consumption fell hand in hand with consumer satisfaction, and positively and significantly related to consumer satisfaction. Using independent sample T test and ANOVA test for gender difference and different working age groups, respectively, we found significant differences between male and female consumers in their mean online expenditures on green fast food products. At least one of the working age groups showed different mean online expenditures toward the green consumption of international fast food products from the rest of the working age groups. Therefore, policy makers and stakeholders should be advised to support eco-labeling and consider consumer preferences according to their age or gender.